"HTTP 503 Error"
There cannot be a more dreadful error than the Web Client not responding when all the different parts of the application seem to be working fine. Also it was a not a firewall or Weblogic issue since those were tested to be working fine.
On further investigation it was found in the Internet Information Services (IIS) for Windows Server the connection drm_pool was in Stopped state. On starting it back the Web Client started responding fine.